Track-type machines are in widespread use in construction, mining, forestry, and other similar industries. The undercarriage of such track-type machines utilizes track assemblies, rather than wheels, to provide ground-engaging propulsion. Such track assemblies may be preferred in environments where creating sufficient traction is problematic, such as the environments identified above. Specifically, rather than rolling across a work surface on wheels, track-type machines utilize one or more track assemblies that include an endless loop of coupled track links defining exterior surfaces, which support ground-engaging track shoes, and interior surfaces that travel about one or more rotatable track-engaging elements, such as, drive sprockets, idlers, tensioners, and rollers, for example.
Typical track chain assembly designs include a track pin either rotatably or fixed to a pair of chain links and a bushing rotatably positioned between the links and about the track pin. Such track chain assemblies can operate in extremely adverse environments in which track joints may be exposed to various abrasive mixtures of water, dirt, sand, rock or other mineral or chemical elements. Consequently, seal assemblies are placed in the track joints to exclude contaminants and retain lubricant within the track joint to facilitate the aforementioned relative movement of the bushings and the track links during use.
These designs have included a variety of seal configurations and positions such as against an inside face of the link or against the track bushing. For example, U.S. Pat. No. 4,204,716 for a “Track Joint With a Thrust Ring and a Seal Ring,” issued May 27, 1980, to John M. Baylor is directed to a track joint with a thrust ring and a seal ring wherein there is a track pin and a cylindrical bushing on the pin and two track links. The end of the bushing and one of the track links present annular surfaces faced toward each other but spaced apart. A thrust ring extends between the annular surfaces and a seal ring is on the thrust ring and extends in two legs radially outwardly from the thrust ring and into contact with the respective annular surfaces for sealing therewith.
An ongoing problem occurs over time when excessive endplay and “pin walking” result in track sections becoming loose or disconnected. Such downtime events can lead to significant losses in productivity for the affected machine.
It will be appreciated that this background description has been created by the inventors to aid the reader, and is not to be taken as an indication that any of the indicated problems were themselves appreciated in the art. While the described principles can, in some respects and embodiments, alleviate the problems inherent in other systems, it will be appreciated that the scope of the protected innovation is defined by the attached claims, and not by the ability of any disclosed feature to solve any specific problem noted herein.